I have owned 5 diesels from 1999-2010. The bad mileage didn't start until the DPF's came into play. Which is why I sold the 2010 and went to the 2007 LBZ Duramax. I get a constant 12mpg hand caluclated pulling my 2011 Keystone Sprinter 323BHS with a dry weight of 8650lbs. My Duramax (6 speed auto) gets 14mpg in town and 19-20hwy. I have a mild tune that does boost the mpg and power up some. 450hp/730tq. I didn't know a 5.4L could pull a 5th

The engineers who came up with the idea of dumping raw diesel into the DPF to clean it should be shot... Right after the engineers who came up with the idea of a DPF... And those right after the politicians who changed the emissions standards...

I had an 05 Chev LLY DRW and I got ~15 mpg empty on the highway. I traded it in with 106,000 KM on the clock (<70K miles) and the new buyer discovered that it had 2 blown head gaskets. Nice. I now have a 2010 Dodge MC CTD DRW and get ~10 mpg on the highway.

RUFFSTUFF wrote:The engineers who came up with the idea of dumping raw diesel into the DPF to clean it should be shot... Right after the engineers who came up with the idea of a DPF... And those right after the politicians who changed the emissions standards...

I said not as much as YOU think. And also said the newer systems, the refined systems, you drive an 08 thats not the newer systems. The newer systems are fine tuned much better, GM has added a 9th injector now to reduce fuel usage for the active regens of which fewer are required due to the engine being able to run hotter and more efficient thanks to the SCR system cleaning up the high NOX levels created from an engine running in that state.

The LMLs are getting fuel economy similar to LBZs, is that great? Not the best, but way better than the LMMs, and your getting 115ft-lb more torque and 47 more hp (than the LBZ)